|Budget Amount *help
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
1. A plupribotent human embryonal carcinoma cell line (NEC14) could be induced to differentiate morphologically by treatment with 10^<-2>M N, N'-hexamethylene-bis-acetamide (HMBA) in vitro. The differentiation accompanied the marked induction of human major histocompatibility antigens (HLA-A, B, C), and the changes of stage specific embryonic antigens (from SSEA-1^-/SSEA-3^+ to SSEA-1^+/SSEA-3^-). Differentiated NEC14 cells expressed mesenchym-associated molecules, vimentin and tenascin ; thus HMBA can induce these cells to certain mesenchymalle elements of embryonal mesoderm.
2. The level of N-myc expression was high in undifferentiated NEC14 cells, but decreased transiently to less than 1/10 of the original level after the HMBA induction. To investigate the role of N-myc gene in the NEC14 cell differentiation, we established several NEC14 transformants expressing exogenous N-myc genes. They showed shorter population doubling time, increased plating efficiency and tumorigenic potential.
3. The level of neuron specific enolase (NSE) in serum was found to be a novel diagnostic marker for immature teratomas and dysgerminomas.
4. From the human teratocarcinoma line PA-1, we established a clonal line that produced a distinct neural rosettes within in vitro multicellular spheroids. This line expressed neuroectodermal antigens such as A2B5, HNK-1 and NC-1, NSE, S-100 protein and vimentin. These rosette showed a strikingly polarized and overlapped deposition of extracellular matrix components including laminin, type IV collagen, heparan sulfate proteoglycan and tenascin.